Comparison Of Single-Chamber Ventricular Pacing And Dual-Chamber Pacing For Bradyarrhythmia

Abstract:Objective To compare the effects of cardiac function atrial fibrillation with single-chamber ventricular and dual-chamber pacing in patients with bradyarrhythmia. Method Reviewed clinical and pacemaker programming datas of 226 patients with permanent pacemaker, selected and received 88 patients of all and followed up. According to cumulative percent ventricular pace (Cum%VP≥50%或<50%) they were assigned to a single-chamber ventricular pacemaker (VVI) (Cum%VP≥50%) group, dual-chamber pacing (Cum%VP≥50%) DDD1 group and dual-chamber pacing (Cum%VP<50%) DDD2 group. Compared and analyzed the following datas,left ventricular end-diastolic diameter(LVEDD), left ventricular ejection fraction (LVEF), constituent of patients on cardiac function before and after pacemaker implanted and the rates of hospitalization for heart failure, the rates of happened of permanent atrial fibrillation after pacemaker implanted in every group.Results:The mean time of follow-up was 40.10±29.14 monthes. At the last time of the follow-up, LVEDD (Respectively,52.53±5.47mm and 50.15±3.99mm) was greater than before (Respectively,49.26±4.35mm and 48.94±3.84mm) implantation in VVI and DDD1 groups (P<0.05)and LVEF (before implanted:57.42±6.39% and 57.73±8.57%; after implanted:48.80±8.67% and 54.81±7.29%) was significant decreased (P<0.05).No change was measured on LVEDD and LVEF after implantation in DDD2 group (P> 0.05).The value of decreased in LVEF and of increased in LVEDD after implantation, VVI group was distinguished (P<0.05) compared with DDD1 group and DDD1 group was distinguished (P<0.05) compared with DDD2 group. The sum of patients for NYHA III and IV VVI group (10/26,38.46%) was significant higher DDD1 group (6/38,15.79%) (P<0.05)and DDD1 group was slightly higher DDD2 group(1/24,4.37%) (P=0.841).The rates of hospitalization for heart failure in the period of follow-up VVI group (34.62%) was significant higher DDD1 group (13.16%) (P<0.05) and DDD 1 group was slightly higher DDD2 group (8.33%) (P>0.05). The rates of incidence for permanent atrial fibrillation VVI group (30.77%) was significant higher DDD1 group (10.53%) (P<0.05). No difference in cumulative percent ventricular pace was observed between VVI (91.31%) and DDD1 (90.50%) group, and there was significant differerce between DDD1 and DDD2 (26.00%) group (P<0.05).Conclusions VVI pacing model that has high percent ventricular pace induce high rate of happened of permanent atrial fibrillation. The same DDD pacing mode, left ventricular enlarged and cardiac function damaged were not significant in decreasing apical right ventricular pacing; Apical right ventricular pacing with high percent partly offset the benefit of hemodynamics due to atrioventricular synchrony in DDD pacing model and increasing left ventricular enlarged and cardiac function damaged.With the same high percent apical right ventricular pacing, VVI pacing model induced left ventricular enlarged, cardiac function damaged, heart failure happened and deteriorated more serious compared with DDD pacing model.